[PATCH v4 1/5] selftests/x86: Use getauxval() to simplify the code in sgx

Tianjia Zhang
2021-02-01T13:28:17Z

Simplify the sgx code implemntation by using library function
getauxval() instead of a custom function to get the base address
of vDSO.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
tools/testing/selftests/sgx/main.c | 24 ++++--------------------
1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 724cec700926..5167505fbb46 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -15,6 +15,7 @@
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
+#include <sys/auxv.h>
#include "defines.h"
#include "main.h"
#include "../kselftest.h"
@@ -28,24 +29,6 @@ struct vdso_symtab {
Elf64_Word *elf_hashtab;
};

-static void *vdso_get_base_addr(char *envp[])
-{
- Elf64_auxv_t *auxv;
- int i;
-
- for (i = 0; envp[i]; i++)
- ;
-
- auxv = (Elf64_auxv_t *)&envp[i + 1];
-
- for (i = 0; auxv[i].a_type != AT_NULL; i++) {
- if (auxv[i].a_type == AT_SYSINFO_EHDR)
- return (void *)auxv[i].a_un.a_val;
- }
-
- return NULL;
-}
-
static Elf64_Dyn *vdso_get_dyntab(void *addr)
{
Elf64_Ehdr *ehdr = addr;
@@ -162,7 +145,7 @@ static int user_handler(long rdi, long rsi, long rdx, long ursp, long r8, long r
return 0;
}

-int main(int argc, char *argv[], char *envp[])
+int main(int argc, char *argv[])
{
struct sgx_enclave_run run;
struct vdso_symtab symtab;
@@ -203,7 +186,8 @@ int main(int argc, char *argv[], char *envp[])
memset(&run, 0, sizeof(run));
run.tcs = encl.encl_base;

- addr = vdso_get_base_addr(envp);
+ /* Get vDSO base address */
+ addr = (void *)getauxval(AT_SYSINFO_EHDR);
if (!addr)
goto err;

--
2.19.1.3.ge56e4f7